Technical Field
The disclosure relates to a photographing device. More particularly, the disclosure relates to a photographing device which comprises a focus adjusting seat.
Background
With the development of technology, a surveillance camera is widely used in security monitoring. For example, the surveillance camera is necessary for personal safety and property protection in families, companies, government agencies, and even general public places. Generally speaking, the surveillance camera may monitor actions in a monitored environment to capture every event.
In prior art, the surveillance camera comprises a lens module. The lens module may be a fixed-focus lens, a variable-focus lens, etc. The structure of the fixed-focus lens is smaller in size and lighter in weight, the image quality of the fixed-focus lens is better, and the fixed-focus lens is cheaper, so the fixed-focus lens has been widely used by consumers. However, the focal length of the fixed-focus lens may not be adjusted by the consumers, so that the usage of the fixed-focus lens is limited. Additionally, even the surveillance camera comprises the variable-focus lens with its focal length can be adjusted by the consumers, but the precision of the variable focus of the surveillance camera may not be upgraded to match a new surveillance camera with high pixel densities which was developed. Accordingly, the image quality of the new surveillance camera may not be enhanced and affected due to the poor variable-focus precision. To sum up, it is necessary to improve the problem of the focal length of the fixed-focus lens which may not be adjusted and provide a focal length adjustment method with a high precision of the variable focus.